Presentation is loading. Please wait.

Presentation is loading. Please wait.

Properties of Liquids and Solids

Similar presentations

Presentation on theme: "Properties of Liquids and Solids"— Presentation transcript:

1 Properties of Liquids and Solids

2 Intermolecular Forces
Intermolecular Forces: weaker interactions that occur between molecules. These are collectively known as Van der Waals forces. Intramolecular Forces: Do not confuse Inter with Intra! Intramolecular forces are how we describe bonding between atoms.

3 Intermolecular Forces

4 Types of IMF London Dispersion Forces View animation online.

5 Types of IMF Dipole-Dipole Forces + - View animation online.

6 Types of IMF Hydrogen Bonding

7 Liquids vs. Solids SOLIDS LIQUIDS IMF Strength Very strong
Fluid Density Compressible Diffusion SOLIDS Very strong N high extremely slow LIQUIDS Stronger than in gases Y high N slower than in gases

8 Liquid Properties Surface Tension
attractive force between particles in a liquid that minimizes surface area

9 Liquid Properties Capillary Action
attractive force between the surface of a liquid and the surface of a solid water mercury

10 Liquid Properties Viscosity: Resistance to flow (molecules with large intermolecular forces).

11 Types of Solids Crystalline - repeating geometric pattern
covalent network metallic ionic covalent molecular Amorphous - no geometric pattern decreasing m.p.

12 Types of Solids Ionic (NaCl) Metallic

13 Types of Solids Covalent Molecular Covalent Network Amorphous (H2O)
(SiO2 - quartz) Amorphous (SiO2 - glass)

14 Types of Solids

15 Types of Solids: Metals
The electron sea model for metals postulates a regular array of cations in a "sea" of valence electrons. (a) Representation of an alkali metal (Group 1A) with one valence electron. (b) Representation of an alkaline earth metal (Group 2A) with two valence electrons.

16 Types of Solids: Metals
Alloy: A substance that contains a mixture of elements and has metallic properties Substitutional Alloy (a): some of the host metal atoms are replaced with atoms similar size metal atom Interstial Alloy (b): some of holes between the metal atoms are filled with smaller atoms

17 Phase Changes

18 Phase Changes Evaporation
molecules at the surface gain enough energy to overcome IMF Volatility measure of evaporation rate depends on temp & IMF

19 Phase Changes Equilibrium
trapped molecules reach a balance between evaporation & condensation

20 Phase Changes temp v.p. IMF v.p. Vapor Pressure
pressure of vapor above a liquid at equilibrium v.p. depends on temp & IMF directly related to volatility temp temp v.p. IMF v.p.

21 Phase Changes Patm b.p. IMF b.p. Boiling Point
temp at which v.p. of liquid equals external pressure depends on Patm & IMF Normal B.P. - b.p. at 1 atm Patm b.p. IMF b.p.

22 Phase Changes IMF m.p. Melting Point equal to freezing point
Which has a higher m.p.? polar or nonpolar? covalent or ionic? polar ionic

23 Phase Changes Sublimation solid  gas
v.p. of solid equals external pressure EX: dry ice, mothballs, solid air fresheners

24 Heating and Cooling curve

25 Heating Curves Temperature Change change in KE (molecular motion)
depends on heat capacity Heat Capacity energy required to raise the temp of 1 gram of a substance by 1°C -

26 Heating Curves Phase Change change in PE (molecular arrangement)
temp remains constant Heat of Fusion (Hfus) energy required to melt 1 gram of a substance at its m.p.

27 Heating Curves Heat of Vaporization (Hvap)
energy required to boil 1 gram of a substance at its b.p. usually larger than Hfus…why? EX: sweating, steam burns, the drinking bird

28 Phase Diagrams We know that different compounds can have different phases. These phases depend on the temperature and pressure of the substance. Temperature Pressure We can then use that information to create a diagram of the different phases called a PHASE DIAGRAM.

29 Looking at Phase Diagrams
The boundaries between phases occur at phase changes (ie. melting, freezing, vaporizing, etc.) S L G Temperature Pressure A - melting, freezing A B B - vaporization, condensation C - sublimation, deposition C

30 Looking at Phase Diagrams
The triple point is where the boundaries converge at one point and all three phases are present at the same time. S L G Temperature Pressure Triple Point

31 Looking at Phase Diagrams
The critical point is the point at which the distinction between the liquid phase and gas phase ceases to exist. S L G Temperature Pressure Critical Point

32 Determining the Melting Point
Find the current pressure Draw a line across the diagram At the boundary between the solid and liquid phase, draw a line down to the temperature Determine the temperature S L G Temperature Pressure 1 atm

33 Phase Change of Water

34 Phase Diagrams Each substance or compound has different melting/freezing points, boiling/condensing points, and sublimation/deposition points. Therefore, each substance or compound has a different phase diagram. Carbon

Download ppt "Properties of Liquids and Solids"

Similar presentations

Ads by Google